Scientists have detected emanating from the nucleus of a galaxy relatively close to our Milky Way flashes of X-rays gradually increasing in frequency that seem to be coming from a white dwarf – a highly compact stellar ember – with a death wish.
The observations made using the European Space Agency’s XMM-Newton orbiting X-ray telescope appear to show a white dwarf nearing the point of no return – called the event horizon – as it orbits the galaxy’s supermassive black hole, according to the researchers.
“It is probably the closest object we’ve ever observed orbiting around a supermassive black hole. This is extremely close to the black hole’s event horizon,” said Megan Masterson, a Massachusetts Institute of Technology doctoral student in physics and lead author of the study that was presented at a meeting of the American Astronomical Society in Maryland this week and will be published in the journal Nature.
The galaxy is located about 270 million light-years from Earth.
The mass of the black hole in the new observations, called 1ES 1927+654, is about a million times greater than the mass of our sun.
The supermassive black hole at the center of the Milky Way, called Sagittarius A*, is about four times more massive than this one. This one appears to have a mass about 10% that of the sun, traveling at nearly half the speed of light. It is traversing the extremely high-energy environment around the black hole and producing X-ray flashes as it orbits in this environment.
The researchers estimated that the white dwarf is orbiting the black hole at about 5% the distance that separates Earth from the sun, or a bit under 5 million miles (8 million km). They said its orbit is stabilizing perhaps because the outer layers of the white dwarf are being sucked into the black hole, providing a kick-back action preventing the object from crossing the event horizon and facing oblivion
